1. The Field of the Invention
This invention relates to tubing clamps. More particularly, the present invention relates to clamping structure which may be repeatedly opened and closed on a length of tubing without causing damage to the tubing.
2. The Prior Art
Flexible tubing fabricated from materials such as plastics and silicone rubber is widely used in many scientific, industrial, and in particular, medical applications. In the medical industry, flexible silicone tubing is fabricated into many different devices.
For example, silicone tubing is used to form one or more portions of in-dwelling catheter sets. Tubing is also used to provide interconnections between medical devices and between medical devices and a patient. Such tubing is often cylindrical but may have a substantially cylindrical shape or some other configuration.
Tubing, both that which is used in the medical industry and in other industries, must routinely be occluded to stop the flow of fluid (either a liquid or a gas under either positive or negative pressure) through the tube. For example, the flow of a medicament through a catheter is routinely stopped by manually applying a clamp to the catheter tubing.
In the medical field, the same properties (e.g., flexibility, small size, and the ability to form several lumens within a length of tubing) which makes silicone rubber particularly suitable for use as a catheter also makes silicone rubber catheters particularly susceptible to damage due to the pinching action of conventional tubing clamps when used alone. Repeated clamping of an unprotected flexible silicone rubber catheter often results in failure of the catheter. The failure of a silicone rubber catheter due to the repeated application of a clamp in a single location is at least very undesirable, and potentially life threatening. Moreover, if the wall thickness of the silicone rubber catheter is increased to provide strength against failure, the outer diameter of a catheter may be too large, and/or the inner too small, for some applications.
Several prior art attempts have been made in an effort to prevent undesirable failures of tubing due to the application of a clamp. One such currently known prior practice includes gluing a reinforcing sleeve at a single location on a length of tubing, such as a catheter, and to direct the user to apply a clamp only at that location. Nevertheless, such an arrangement still permits clamping to occur, both inadvertently and deliberately, at locations along the tubing other than at the location of the reinforcing sleeve.
Moreover, some portions of a length of tubing are more susceptible to damage from application of a clamp than others. For example, portions of tubing adjacent to connectors attached to the end of the tubing are particularly likely to fail if a clamp is applied thereto. Still further, even the inclusion of a reinforcing sleeve may not prevent damage due to repeated clamping at the same location. If clamping at a single location occurs repeatedly, the tubing may fail regardless of the interposition of a reinforcing sleeve and in some instances the reinforcing sleeve itself may fail.
The devices previously available in the art do little or nothing to address these long existing problems of tubing failure which persist even when a reinforced sleeve is attached to the tubing.